I'm a firm believer that squats are ultimately the best exercise for making gains, as they're a multijoint movement that utilizes all the musculature in the legs as well as the glutes.

Many recreational lifters suffer from CLS—Chicken Leg Syndrome—due in no small part to years of prioritizing chest and arms over their thighs. You can't change what's already done but, going forward, prioritizing legs is key.

If you're afflicted with CLS, Calum recommends two important ways to help bring them up so if legs are a weak point, I'd suggest training them twice a week, and making squats a priority in your workout!